Modes of communication in computer networks refer to how information transmits from one place to another.
Data Transmission mode defines the direction of the flow of information between two communication devices. It specifies the direction of the flow of information from one place to another in a computer network. We also call it Data Communication or Directional Mode.
It is due to the transmission mode. The transmission mode is also known as the communication mode. Each communication channel has a direction, and transmission media provide guidance. Therefore, the transmission mode is also known as a directional mode. Open System Interconnection (OSI). The layer Model has dedicated the Physical Layer to data transmission in the network. It mainly decides the direction of data in which the data needs to travel to reach the receiver system or node.
This tech article will teach you about different data transmission modes based on the direction of exchange, synchronization between the transmitter and receiver, and the number of bits sent simultaneously in a computer network.
We classify the different modes of communication in computer networks on the following basis:
- The direction of exchange of information
- Synchronization between the transmitter and the receiver
- The number of bits sent simultaneously in a network.
We classify the modes of network communication into three types based on the direction of exchange of information:
- Simplex
- Half-Duplex
- Full Duplex
It is the mode of communication in a computer network in which the communication takes place in only one direction. The transmission is unidirectional, i.e., the data can flow only in one direction. It implies that a sender can only send data but not receive it. Similarly, the receiver cannot send data back.
We mainly use it in the business field and sales that do not require any corresponding reply. It is similar to a one-way street.
- Data we send to an electronic notice board found in Train Stations and Airports.
- The radio station is a simple channel as it transmits the signal to the listeners but never allows them to send them back.
- The same is the case with the television transmission on the radio station.
- The keyboard and monitor are examples of the simplex mode, as a keyboard can only accept the data from the user, and the monitor can only display the data on the screen.
- The main advantage of the simplex mode is that it uses the total capacity of the communication channel during transmission.
- It can utilize the entire bandwidth of the communication channel so that more data can transmit at a time.
- Due to the unidirectional data flow, it has the least or no data traffic issues.
- This transmission mode is not so popular because we cannot perform two-way communication between the sender and receiver in this mode.
- Since the communication is unidirectional, therefore it has no inter-communication between devices. There is no mechanism to transmit information back to the sender (There is not any mechanism for acknowledgment).
Simplex Mode of Data Communication
We also refer to it as Semi-Duplex. It is the communication in the computer network in which data flow occurs in both directions but not at the same time. Each station can send or receive a signal simultaneously, and both processes cannot co-occur. When one device is sending, the other can only receive and vice-versa. Therefore, the entire bandwidth of the communication channel is utilized in one direction at a time.
- Transaction-oriented systems employ half-duplex communication, i.e., the communication between a computer and a credit card machine.
- A Walkie-talkie is an example of the Half-duplex mode. In Walkie-talkie, one Party speaks, and another Party listens. After a pause, the other speaks, and the first Party listens. Simultaneous speaking of both will create a distorted sound that the listener cannot understand.
- Internet Browsers.
- Both devices can send and receive the data and utilize the entire communication channel bandwidth during data transmission.
- It facilitates the optimum use of the communication channel. In half-duplex mode, it is possible to detect an error, and if any error occurs, the receiver requests the sender to retransmit the data.
- The most significant disadvantage of the Half-Duplex mode of communication in computer networks is the time delay. This delay occurs when one device sends the data; another must wait.
- One cannot establish two-way communication at the same time.
Half-duplex Mode of Data Communication
It is the communication mode in which data flow takes place in both directions at the same time. It is the fastest bi-directional (two-way) communication in which both stations can transmit and receive the data simultaneously.
Full-Duplex mode has double bandwidth as compared to the half-duplex. It is like a two-way street with traffic flowing in both ways simultaneously. The channel divides its capacity between the two directions of communication. Networks use this mode when they require communication in both directions simultaneously.
- A telephone network is one typical example of a full-duplex network communication mode. When two people communicate with each other by telephone, both can talk and listen simultaneously.
- Also, the full-duplex way is the most suitable for data communication between computers.
- Both stations can send and receive the data at the same time.
- It is the fastest communication between devices since two-way communication can be carried out simultaneously in both directions.
- If no dedicated path exists between the devices, then the capacity of the communication channel is divided into two parts.
- It has improper channel bandwidth utilization as two separate ways exist for two communicating devices.
Full-duplex Mode of Data Communication
We classify the modes of communication in computer network into the following two types based on the synchronization between the transmitter and the receiver:
It is a mode of communication that introduces a start and a stop bit in the message during transmission. The start and stop bits ensure that the data is transmitted correctly from the sender to the receiver.
In an asynchronous mode of communication, we can send data bits at any time. The devices send messages at irregular intervals and can send only one data bit at a time. This type of transmission mode is best suited for short-distance data transfer.
Asynchronous means ‘asynchronous at the byte level,’ but the bits are still synchronized. Generally, the start bit is ‘0’, and the end bit is ‘1’. The time duration between each character is the same and synchronized.
Data input from a keyboard to the computer is an example of Asynchronous Transmission.
- It is a cheap and effective mode of transmission.
- Data transmission accuracy is high due to start and stop bits.
The data transmission can be slower due to the gaps present between different blocks of data.
Asynchronous Transmission
It is a mode of communication in which a communicating device sends bits without any start/stop bits or gaps between them. The same system clock paces both the sender and receiver. One achieves synchronization this way.
In a Synchronous data transmission mode, a device transmits bytes as blocks in a continuous stream of bits. Since there is no start and stop bits in the message block. It is the responsibility of the receiver to group the bits correctly. The receiver counts the bits and groups them into eight bits as they arrive. It then continuously receives the information at the same rate as the transmitter. It also listens to the messages even if no bits are transmitted.
In synchronous mode, a device sends bits successively with no separation between each character, so it becomes necessary to insert some synchronization elements with the message; “Character-Level Synchronization.”
Typical examples are communication in CPU, RAM, etc.
Transmission speed is fast as there is no gap between the data bits.
It is costly.
Synchronous Transmission
We classify the modes of network communication into the following two types based on the number of bits sent simultaneously in the network:
It is a mode in which the data bits are sent simultaneously. In other words, there is a transmission of n-bits at the same time simultaneously.
Multiple transmission lines are used in such modes of transmission. So, we can send numerous data bytes transmitted in a single system clock. This transmission mode is used when a large amount of data has to be sent in a shorter duration. We primarily use it for short-distance communication.
For n-bits, we need n-transmission lines. So, the complexity of the network increases, but the transmission speed is high. If two or more transmission lines are too close, there may be a chance of interference in the data, degrading the signal quality.
Data transmission between computer and printer is an example of the parallel transmission mode.
- Data transmission speed is high due to the n-transmission channel.
- It is easy to program or implement.
- Interference in data bits, likewise in video conferencing.
- It requires more transmission channels and hence is cost-ineffective.
It is a mode in which the data bits are sent serially one after the other over the transmission channel.
The device that is communicating receives data bits in synchronization with one another. It needs a single transmission line for communication. So, there is a challenge in synchronizing the transmitter and receiver.
The system takes several clock cycles in serial data transmission to transmit the data stream. In this mode, one can maintain the data integrity by sending the data bits in a specific order, one after the other. This transmission mode is best suited for long-distance data transfer, or the amount of data sent is relatively tiny.
Data transmission between two computers using serial ports.
- The number of wires and complexity is more diminutive.
- It is cost-effective.
- We can use it for long-distance data transmission as it is reliable.
The Data transmission rate is slow due to a single transmission channel.
Moreover, you may read about the OSI Network Model Layers.
